An automotive millimeter-wave radar that detects a distance and a relative speed to a vehicle in front by the use of an electromagnetic wave in a millimeter-wave band is applied to a cruise control and safety measures, for example, for reducing damage to a driver in case a vehicle collision is inevitable. In such an automotive millimeter-wave radar, to achieve a transmission signal, a method of multiplying a low frequency is mostly employed. However, in this case, lots of frequency components exist in a module, so that it is extremely difficult to meet overseas EMI standards (such as the FCC).
In an automotive millimeter-wave radar, a radar module generally includes a radio-frequency package equipped with a radio-frequency device for a radar device, a control/interface substrate that supplies a bias signal and a control signal to the radio-frequency package, a waveguide plate, and the like. To meet the EMI standards, in conventional technologies, the entire radar module is generally covered with a metal cover.
However, when the entire radar module is covered with the metal cover, it is necessary to provide an expensive enclosure and the like. Therefore, to achieve a low cost, there has been expected to develop a countermeasure meeting the EMI standards within the radio-frequency package.
In a technology disclosed in Patent document 1, an integrated-circuit component for radio-frequency signal and a dielectric substrate are mounted on a metallic base member, and a microstrip line is formed on the dielectric substrate. The base member on which the integrated-circuit component for radio-frequency signal and the dielectric substrate are mounted is covered with a metallic frame member and a metallic cover member. The integrated-circuit component for radio-frequency signal mounted on the base member is supplied with a bias via a bias terminal.
Patent document 1: Japanese Patent Application Laid-open No. 2000-31712